Just bought the V6 on here

[andytoad]

Hello all,
Need a little advice, I have just bought a lovely TE V6, that runs at 4 or 2 OHM. Is it essential for reliability that I match the cab Ohmage too?

I can make 4ohm from my two SWR cabs, but occasionally I like to use one at 8 ohms. Does this mean I will end up with more that valves glowing if a use an 8 ohm speaker when the amp is running at 4 or 2 ohms?

thanks in advance for you knowlegable advice!

Andrew

[hamfist]

With valve output stages, the ohmage must be matched. If you run an 8 ohm load from a valve amp's 4 ohm output you risk trashing your output transformer. There is not the leaway that SS power amps have with only minimum load requirements.

[MarkG3]

I asked the same question when I had a V6 and the general answer was that it was risky - as above.

But others said it was fine, I preferred not to risk it myself just incase.

[voxpop]

Also if you are new to valves.... Don't turn the amp on with no speakers connected. This can cause damage to the transformers.

Hope this helps.

[hamfist]

[quote name='S9_S12_Bass' timestamp='1360681014' post='1974502']
I asked the same question when I had a V6 and the general answer was that it was risky - as above.

But others said it was fine, I preferred not to risk it myself just incase.
[/quote]

It's true that some amps, and output transformers, are more forgiving than others. The general advice with valve amps is to always match impedances though. If you don't you are taking a risk.

[andytoad]

Ok all, thanks for the advice, i shall stick to 4 ohms!

[4 Strings]

Surprised there's not an 8 Ohm option. Sounds like its been designed for use with multiple cabs, with the 2 Ohm option.

With tranny amps, they can drive a range of speaker impedance but the power output reduces with rising impedance. They do struggle with 2 Ohms though, few can do that one - its almost a short circuit at lower frequencies!

Can a valve power section drive a higher impedance ok, but needs care driving lower? (ie could the OP's V6 drive 8 Ohms ok - set to 4 Ohms?)

>Forget to add my expression of jealously of the V6!

Edited February 12, 2013 by 4 Strings

[Dad3353]

[quote name='4 Strings' timestamp='1360708202' post='1975315']...Sounds like its been designed for use with multiple cabs, with the 2 Ohm option...[/quote]

There are 6 x KT88 valves in there; 'multiple cabs' would be almost an understatement. Cab power handling is better now than 'back then', but this is not a bedroom practice amp. They were designed to run a (very...) full stack.

[quote name='4 Strings' timestamp='1360708202' post='1975315']...Can a valve power section drive a higher impedance ok, but needs care driving lower? (ie could the OP's V6 drive 8 Ohms ok - set to 4 Ohms?)...[/quote]

The answer to this is: 'Sometimes, yes...', but finding out with any one amp with any one cab can be risky. Unless someone else has already done this successfully with the V6, I would suggest that it's not a good idea to find out, as it may (well...) destroy the amp, or, at least, it's o/p tranny. Some amps are (slightly...) more tolerant than others, but...

Hope this helps...

[umph]

[quote name='4 Strings' timestamp='1360708202' post='1975315']
Surprised there's not an 8 Ohm option. Sounds like its been designed for use with multiple cabs, with the 2 Ohm option.

With tranny amps, they can drive a range of speaker impedance but the power output reduces with rising impedance. They do struggle with 2 Ohms though, few can do that one - its almost a short circuit at lower frequencies!

Can a valve power section drive a higher impedance ok, but needs care driving lower? (ie could the OP's V6 drive 8 Ohms ok - set to 4 Ohms?)

>Forget to add my expression of jealously of the V6!
[/quote]

higher impedances are bad, lower are okay